When neither unlinkat nor dirent::d_type is available, _Dir::advance
leaves every entry with file_type::none, so __erase takes the unlink
path. Without unlinkat _Dir::do_unlink ignores its is_directory
argument and always calls fs::remove, i.e. ::remove, which retries as
rmdir for a directory. Unlinking a non-empty directory therefore
reports the rmdir errno for "not empty" rather than the EPERM or EISDIR
that unlink on a directory would give, the retry-as-directory path is
not taken, and remove_all fails with (uintmax_t)-1 on the first
non-empty sub-directory. POSIX allows either ENOTEMPTY or EEXIST for
that condition, so accept both, but only when unlinkat is unavailable.
An empty directory of unknown type is still removed correctly, because
::remove falls back to rmdir and succeeds, so reproducing this needs a
tree at least two levels deep.
PR libstdc++/127555
libstdc++-v3/ChangeLog:
* src/c++17/fs_dir.cc (recursive_directory_iterator::__erase):
Retry as a directory when unlink fails with ENOTEMPTY or EEXIST
and unlinkat is not available.
Signed-off-by: Gokbey Gazi Keskin <[email protected]>
---
Tested on x86_64-pc-linux-gnu.
libstdc++-v3/src/c++17/fs_dir.cc | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/src/c++17/fs_dir.cc b/libstdc++-v3/src/c++17/fs_dir.cc
index f6860e26411..7cced0db823 100644
--- a/libstdc++-v3/src/c++17/fs_dir.cc
+++ b/libstdc++-v3/src/c++17/fs_dir.cc
@@ -514,13 +514,23 @@ fs::recursive_directory_iterator::__erase(error_code*
ecptr)
{
// We did not have a cached type, so it's possible that top.entry
// is actually a directory, and that's why the unlink above failed.
+ const int err = ec.value();
#ifdef EPERM
// POSIX.1-2017 says unlink on a directory returns EPERM,
// but LSB allows EISDIR too. Some targets don't even define EPERM.
- if (ec.value() == EPERM || ec.value() == EISDIR)
+ bool is_dir = err == EPERM || err == EISDIR;
#else
- if (ec.value() == EISDIR)
+ bool is_dir = err == EISDIR;
#endif
+#if ! _GLIBCXX_HAVE_UNLINKAT
+ // Without unlinkat, _Dir::unlink uses ::remove, which retries as
+ // rmdir for a directory. Unlinking a *non-empty* directory then
+ // reports "directory not empty" instead of the errno for unlink
+ // on a directory, so treat that as a directory too. POSIX allows
+ // either ENOTEMPTY or EEXIST for that condition.
+ is_dir = is_dir || err == ENOTEMPTY || err == EEXIST;
+#endif
+ if (is_dir)
{
// Retry, treating it as a directory.
top.entry._M_type = file_type::directory;
--
2.43.0
